Processes for regeneration of organocations

ABSTRACT

The present disclosure concerns processes for regenerating organocations from perchlorate-rich waste products, more specifically transformation of water-insoluble organocation-perchlorate salt, originating from perchlorate-removal water treatment processes, into a water-soluble perchlorate salt for reusing same.

TECHNOLOGICAL FIELD

The present disclosure concerns processes for regenerating organocationsfrom perchlorate-rich waste products, more specifically transformationof water-insoluble organocation-perchlorate salt, originating fromperchlorate-removal water treatment processes, into a water-solubleperchlorate salt for reusing same.

BACKGROUND ART

References considered to be relevant as background to the presentlydisclosed subject matter are listed below:

-   -   WO 2014/128702

Acknowledgement of the above references herein is not to be inferred asmeaning that these are in any way relevant to the patentability of thepresently disclosed subject matter.

BACKGROUND

Perchlorate is one of the contaminants increasingly found in wastewater,groundwater, surface water and soil. Perchlorate is known for itsadverse effects to human health by interfering with iodide uptake intothe thyroid gland. It is highly soluble in water and organic solvents,and is difficult to complex with common organic or inorganic cations.Large scale operations for removal of perchlorate from contaminatedwater, e.g. industrial waste water, require regeneration processes ofthe perchlorate-removal treatment media, often resulting in theformation of perchlorate-rich brines, which then need to be furtherprocessed, rendering the process costly and environmentally problematic.

This is of significant magnitude when highly perchlorate-contaminatedwater is to be treated, i.e. water containing >10 ppm of perchlorate,where the need to treat the perchlorate-rich brines often renders theremoval process economically unfavorable.

Other proposed methods to treat perchlorate-rich waste products fromwater treatment processes involve bacterial decomposition ofperchlorate. However, such processes are relatively slow, suitable fortreating relatively low concentrations of perchlorate in the wasteproduct, and require constant monitoring and maintenance of strictconditions throughout the process.

Therefore, there is a need for an efficient and rapid process for theregeneration of a perchlorate-rich waste product into a usable reagentfor further use in water-treatment processes, which is also costeffective.

GENERAL DESCRIPTION

Perchlorate is considered to be an anion which does not tend toprecipitate from aqueous solutions due to its low charge density, whichlimits its ability to form ionic bonds with conventional precipitatingcations. In WO 2014/128702, the inventors of the present invention havedemonstrated a process for precipitation of perchlorate by usingbenzalkonium (BNZ) as a cation, resulting is precipitation ofwater-insoluble benzalkonium-perchlorate salt. This process is used toeffectively remove high concentrations of perchlorate fromperchlorate-contaminated aqueous solutions, e.g. waste water.

The present disclosure aims at providing a process for treatingperchlorate-rich waste products that are generated during processes forremoval of perchlorate ions from contaminated water. More specifically,the present disclosure concerns processes for treating water insolubleorganocation-perchlorate salts, such as those generated in a processdescribed in WO 2014/128702, in order to regenerate the organocation forfurther use.

The present disclosure is based on the realization that differentperchlorate salts have different solubility in various solvents, suchthat different precipitation reactions can result in recovery of theorganocations from the organocation-perchlorate salt.

Thus, in a first aspect, this disclosure provides a process forrecovering a water-soluble organocation salt from a substantiallywater-insoluble organocation-perchlorate, the process comprising:

(a) contacting said substantially water-insolubleorganocation-perchlorate with a first solution containing a first saltdissolved in an organic solvent, the first salt consisting of a metalcation and a balancing anion, under conditions permitting precipitationof metal-perchlorate salt and formation of a second salt dissolved insaid organic solvent, the second salt consisting of the organocation andthe balancing anion;

(b) separating the metal-perchlorate salt from the organic solvent inwhich the second salt is dissolved; and

(c) separating the organic solvent from the second salt to obtain saidsecond salt, said second salt being water-soluble.

In other words, the process is based on the following chemical Equation(I):

wherein: X is an organocation, M is a metal cation, Y is a balancinganion, and n is an integer between 1 and 3.

As evident from the equation above, the process of this disclosureenables obtaining the organocation in a water-soluble form (e.g. awater-soluble salt) by recovery from a water-insoluble salt of theorganocation. This is permitted by taking advantage of the difference insolubility of different salts of the organocation in various organicsolvents. The water-insoluble organocation-perchlorate salt (XClO₄) isdissolved in organic solvent in which a first salt containing a metalcation and a balancing anion is also dissolved. Thedissolution-precipitation reaction results in the formation of ametal-perchlorate salt, which is insoluble in the organic solvent andhence precipitates out of the solvent, and a second salt (XY, containingthe organocation and the balancing anion) which is highly soluble inboth the organic solvent and water. Thus, the organocation is recoveredfrom its water-insoluble form and transformed into a water-soluble salt,such that it may be re-used in water treatment processes.

In the context of the present disclosure, referring to a compound orcomponent as soluble (or any lingual variation thereof) is meant todenote that the compound or component is dissolvable in a liquid (inwater or organic solvent, depending on the context) in a substantiveextent.

Similarly, when referring to a compound or a component as insoluble orsubstantially insoluble (or any lingual variation thereof), it is meantto denote that the compound or component has a negligible solubility ina specific liquid. The solubility (as well as insolubility) is typicallyprovided by a Ks value of the component in a given liquid, which is theequilibrium constant of said component in said liquid. The higher the Ksvalue, the higher the solubility of said compound or component in saidliquid. All solubility values described herein, unless specificallynoted otherwise, are provided at room temperature (20-35° C.) andatmospheric pressure.

In some embodiments, the water-insoluble organocation-perchlorate salthas a water solubility of at most 5×10⁻⁴ M (i.e. Ks≤2.5×10⁻⁷).

In other embodiments, the water-insoluble organocation-perchlorate salthas a solubility of at least 0.05 M in the organic solvent (i.e.Ks≥0.01). In some embodiments, the water-insolubleorganocation-perchlorate salt has a solubility of at least 0.01 M in theorganic solvent (i.e. Ks≥0.01).

In some other embodiments, the metal-perchlorate salt has a solubilityof at most 10⁻³ M in the organic solvent (i.e. Ks≤10⁻⁶).

In yet other embodiments, the second salt has a water solubility of atleast 10⁻⁴ M (i.e. Ks≥10⁻⁸).

It should be noted, that the term solution should be given its broadestdefinition to encompass a liquid state in which one component isdissolved in another or in a liquid medium.

Due to its low solubility in the organic solvent, the metal-perchloratesalt is said to precipitate out of the organic solvent. The termprecipitating, or any lingual variation thereof, refers to the formationof solid perchlorate salt which is substantially insoluble is theorganic solvent and thus sediments (i.e. precipitates) out of theorganic solvent as a solid product. By the process of precipitation, theseparation of perchlorate from the organocation is obtained.

The term organocation refers to a cation (a positive-charge ion) thathas an organic moiety. In some embodiments, the organocation isquaternary ammonium ion. In other embodiments, the organocation is aquaternary ammonium cation having a structure of formula (I):

whereinR is a —(C₃-C₁₈)alkyl;R₁ and R₂ are each independently selected from H and —(C₁-C₆)alkyl; andR₃ is one or more substituents, each independently selected from H,—(C₁-C₆)alkyl, —(C₁-C₆)alkoxy, —NHCO(C₁-C₆)alkyl, —OH, and —NH_(2.)

As used herein, alkyl carbon chains, if not otherwise specified, containfrom 1 to 18 carbons, or 1 or 2 or 3 to 18 carbons, and are straight orbranched. The term “C₁-C₆ alkyl” should be understood to encompass anystraight or branched alkyl moiety having 1, 2, 3, 4, 5 or 6 carbonatoms. Exemplary alkyl groups include, but are not limited to, methyl,ethyl, propyl, isopropyl, isobutyl, n-butyl, sec-butyl, tert-butyl, andisohexyl.

As used herein, “alkoxy” refers to R′O—, in which R′ is a (C₁-C₆)alkyl.

In reference to group R₃, substituent on an aryl moiety, it is said thateach represents “one or more substituent”, namely one or two or three orfour or five substitutions on the ring. When the ring bears one R₃group, this single group may be a substituent positioned on any one ofthe ring positions, i.e., ortho, meta, or para. When the ring issubstituted by two R₃ substituting groups, the two groups may be onneighboring carbon atoms (ortho to each other), or may be separated byone or more ring carbon atoms. When the ring is substituted by three ormore substituting groups, the groups may be substituted on any one ofthe ring positions at any variation available.

In some embodiments, R₁ and R₂ are each independently selected from Hand a methyl.

In other embodiments, R₃ is one or more substituent, each independentlyselected from H, methyl, ethyl and propyl.

In additional embodiments, R₁ and R₂ are both H, and R₃ is a methyl.

In some other embodiments, R₁, R₂ and R₃ are H.

According to some embodiments, R is a —(C₆-C₁₈)alkyl. In suchembodiments, R may be a —(C₁₂-C₁₈)alkyl.

In additional embodiments, the compound of formula (I) is benzalkonium,wherein R is —(C₃-C₁₈)alkyl. In some additional embodiments, thecompound of formula (I) is benzalkonium, in which R is —(C₃-C₁₈)alkyl.

In further embodiments, the compound of formula (I) is a benzalkoniumsalt, in which R is —(C₁₂-C₁₈)alkyl.

In the process of this disclosure, the organocation-perchlorate isreacted with a first salt that contains a metal cation and a balancinganion. The reaction results in the formation of a metal-perchlorate saltor complex and a second salt that contains the organocation and thebalancing anion. The metal can be any suitable metal ion, typically analkali or earth-alkali metal, e.g. sodium, potassium, calcium,magnesium, etc. In some embodiments, the metal is potassium. In otherembodiments, the metal is sodium. In further embodiments, the metal iscalcium. In yet further embodiments, the metal is magnesium.

The balancing anion can be any suitable balancing anion that forms afirst salt with the metal cation that is soluble in the organic solventand a second salt with the organocation which is soluble in both theorganic solvent and water, such as hydroxyl, halide, carboxyl, oxyanion,etc.

In some embodiments, the balancing anion is hydroxyl (OH⁻). In otherembodiments, the balancing anion is a halide or a pseudo-halide.

The organic solvent is selected such that it permits high solubility ofthe organocation-perchlorate, the first salt and the second salt,however in which metal-perchlorate is substantially insoluble. In orderto facilitate easy separation of the products of the reaction from theorganic solvent, the organic solvent is typically selected to have a lowboiling temperature, e.g. below about 90° C.

In some embodiments, the organic solvent may be selected from ethanol,isopropanol, acetone, methanol, and mixtures thereof.

In other embodiments, the solvent is ethanol.

As noted above, it is often desired to separate the reaction productsfrom the organic solvent in order to permit utilization of the reactionproducts. Thus, in some embodiments, the separating in step (c) may becarried out by evaporation of the organic solvent. In other embodiments,the separating in step (c) may be carried out by distillation.

In such embodiments, the process may further comprise condensing vaporsof the organic solvent formed during evaporation or distillation of step(c) to obtain a condensate of organic solvent. The condensate of theorganic solvent may then by utilized as a by-product of the process, or,in some embodiments, the condensate may be reintroduced into the processin step (a).

Separating of the precipitated metal-perchlorate at step (b) may becarried out by any suitable process in which solids are separated fromliquids, e.g. sedimentation, decantation, filtration, clarification,centrifugation, cyclonic separation, flotation, etc. In someembodiments, the separating in step (b) is carried out by sedimentation,decantation, filtration or a combination thereof.

The metal-perchlorate salt or complex separated in step (b) may, by someembodiments, be further treated to remove the organic solvent from themetal-perchlorate salt.

The organic solvent may be removed from the metal-perchlorate salt bycentrifugation or evaporating, and in some embodiments, the organicsolvent removed from the metal-perchlorate salt is reintroduced into theprocess in step (a) (e.g. when removed by evaporation, the organicsolvent vapors may be condensed, and the condensate may then beintroduced into the process at step (a)).

In processes of the present disclosure, the water-insolubleorganocation-perchlorate salt may be introduced into the process at step(a) in solid form (e.g. power, granules, flakes, pellets, etc.).However, as the water-insoluble organocation-perchlorate salt istypically a product of a perchlorate removal water treatment process,such as that described in WO 2014/128702, the water-insolubleorganocation-perchlorate salt is typically introduced into step (a) inthe form of an aqueous slurry or sometimes as homogenous oily foam. Theterm aqueous slurry refers to a liquid mixture of particles of the waterinsoluble organocation-perchlorate salt and an aqueous medium (e.g.water).

In step (a), the water-insoluble organocation-perchlorate salt iscontacted with a solution of the first salt in the organic solvent,under conditions permitting the dissolution-precipitation reaction totake place. As used herein, the term contacting, or any lingualvariation thereof, refers to the bringing together of the material to betransformed (i.e., the water insoluble organocation-perchlorate salt)and the first salt in such a way to allow intimate contact between them.The contacting may be, for example, by cross-flow of liquids, by mixing,flowing the solution over a substrate of the organocation-perchloratesalt, etc.

In some embodiments, contacting may be carried out by mixing. Mixing maybe carried out by a variety of mixing techniques known in the art. Suchtechniques may include, but are not limited to, static mixing,cross-counter flow, pneumatic and/or electrically operated mixingstirrer/paddle, magnetic stirring, etc.

Mixing may be carried out by using a reaction vessel, a reaction chamberor a reactor, which may be of any size or shape, and constructed of anymaterial suitable to withstand acidic and/or basic pH conditions, heatand pressure. Non-limiting examples are a pipe reactor, tank reactor,fixed bed reactor, a moving bed reactor, a fluidized bed reactor, acirculating fluidized bed reactor, etc.

The liquids used in the processes of the invention may be fed into thereaction vessel via a liquid feeding unit, capable of transferring saidliquid to said reaction vessel. The feeding unit is typically connectedto the reaction vessel through appropriate tubing system. Said unit mayhave metering means for measuring exact amount of liquids transferred tothe reaction vessel.

The reactor may further comprise a temperature control unit, such as aheating/cooling unit or a heat exchanger, along with means forcontrolling said unit in response to autothermic or the absence ofautothermic conditions within the reaction chamber; internal temperaturegauges for monitoring the reaction's temperature; condensation units,scrubbing units and absorption columns, to afford treatment of gaseousreaction products and gaseous contaminants; baffles of variousgeometries for controlling the flow profile of substance within thereactor; a top plate that is movable with respect to an outer body ofthe reactor; a base plate that is movable with respect to an outer bodyof the reactor; reactants inlets at various angles; products outlets atvarious angles, etc.

In order to facilitate tailoring of the required amount of the firstsalt to be mixed with the water-insoluble organocation-perchlorate salt,the process may further comprise determining theorganocation-perchlorate concentration in feed of the aqueous slurryprior to mixing with the first salt. Additionally, or alternatively, theprocess may comprise determining the organocation concentration in thesolution during or after mixing in order to establish the efficiency ofthe organocation recovery. The concentration determination, which mayalso by carried out in-situ during the mixing, may be carried out by anysuitable technique known in the art, such as (but not limited to), ionspecific electrode, titration, potentiometric titration, gravimetricanalysis, chromatography, etc.

In some embodiments, the process further includes adjusting theconcentration of the first salt in the first solution according to theconcentration of the water-insoluble organocation-perchlorate salt inthe feed stream.

The conditions permitting reaction between the water-insolubleorganocation-perchlorate salt and the first salt may be selected from atleast one of mixing time, mixing speed, temperature, pH, molar ratiobetween the reaction components, concentrations of the components, etc.

In some embodiments, the contacting may be carried out for a period oftime of between of at least 1 minute.

In some embodiments, the contacting may be carried out at a temperatureranging between about −2 and 80° C. In other embodiments, contacting maybe carried out at a temperature ranging between about 10 and 50° C.

According to some embodiments, the concentration of the water-insolubleorganocation-perchlorate salt in the aqueous slurry that is fed intostep (a) is between about 1 and 100%.

According to some other embodiments, the molar ratio between thewater-insoluble organocation salt and the first salt is in a rangebetween 1:1 and 1:10.

In another aspect, the present disclosure provides a process forobtaining water-soluble benzalkonium-hydroxide from substantiallywater-insoluble benzalkonium-perchlorate, the process comprising:

(a) contacting an aqueous slurry of benzalkonium-perchlorate with afirst solution containing potassium hydroxide dissolved in an organicsolvent, under conditions permitting precipitation ofpotassium-perchlorate salt and formation of benzalkonium-hydroxidedissolved in said organic solvent;

(b) separating the precipitated potassium-perchlorate from the organicsolvent in which the benzalkonium-hydroxide is dissolve; and

(c) separating the organic solvent from the benzalkonium-hydroxide toobtain a water-soluble benzalkonium-hydroxide,

benzalkonium having the following formula (I):

whereinR is a —(C₃-C₁₈)alkyl;R₁ and R₂ are each independently selected from H and —(C₁-C₆)alkyl; and

R₃ is one or more substituents, each independently selected from H,—(C₁-C₆)alkyl, —(C₁-C₆)alkoxy, —NHCO(C₁-C₆)alkyl, —OH, and —NH_(2.)

Unlike typical regeneration processes of brines from waste-watertreatments, in processes of this disclosure, all of the process productsmay be used per-se or utilized as starting materials for otherprocesses. For example, the organic solvent, after its separation fromthe second salt and/or the metal-perchlorate salt, may be used as suchin other processes, or may be re-introduced into the process of thisdisclosure at step (a). In another example, when the metal is potassium,the potassium perchlorate product may be used as an oxidizer to anyother desired purpose. When the organocation is benzalkonium, thewater-soluble benzalkonium salt may be used in waste-water treatmentprocesses to permit removal of perchlorate ions therefrom (such as thosedescribed in WO 2014/128702).

As disclosed herein, the processes of the present disclosure involvenumerous process steps which may or may not be associated with othercommon physical-chemical processes so as to achieve the desired purityand form of each of the isolated components.

As used herein, the singular form “a”, “an” and “the” include pluralreferences unless the context clearly dictates otherwise. For example,the term “a compound of formula (I)” may independently include aplurality of compounds of formula (I), including mixtures thereof.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise”, and variations such as“comprises” and “comprising”, will be understood to imply the inclusionof a stated integer or step or group of integers or steps but not theexclusion of any integer or step or group of integers and steps.

As used herein, the term “about” is meant to encompass deviation of ±10%from the specifically mentioned value of a parameter, such astemperature, pressure, concentration, etc.

Whenever a numerical range is indicated herein, it is meant to includeany cited numeral (fractional or integral) within the indicated range.The phrases “ranging/ranges between” a first indicate number and asecond indicate number and “ranging/ranges from” a first indicate number“to” a second indicate number are used herein interchangeably and aremeant to include the first and second indicated numbers and all thefractional and integral numerals therebetween. It should be noted thatwhere various embodiments are described by using a given range, therange is given as such merely for convenience and brevity and should notbe construed as an inflexible limitation on the scope of the invention.Accordingly, the description of a range should be considered to havespecifically disclosed all the possible sub-ranges as well as individualnumerical values within that range.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable sub-combination or as suitable in any other describedembodiment of the invention. Certain features described in the contextof various embodiments are not to be considered essential features ofthose embodiments, unless the embodiment is inoperative without thoseelements.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosedherein and to exemplify how it may be carried out in practice,embodiments will now be described, by way of non-limiting example only,with reference to the accompanying drawings, in which:

FIG. 1 is a block diagram of a process according to an embodiment ofthis disclosure.

FIG. 2 is a block diagram of process according to another embodiment ofthis disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

The following description exemplifies how processes of this disclosuremay be used to recover a water-soluble form of benzalkonium (BNZ) fromwater insoluble benzalkonium-perchlorate (BNZ-ClO₄) complex. Therecovery process is based on the different in solubility of BNZ-ClO₄complex exhibits in water compared to ethanol (Table 1).

TABLE 1 ClO₄ equilibrium concentration and solubility in differentsolvents Complex/ ClO₄ equilibrium Solubility precipitant Matrix conc.[mM] product [Ks] BNZ-ClO₄ Salt water 0.81 6.56 × 10⁻⁷ BNZ-ClO₄Deionized water 0.20 4.04 × 10⁻⁸ BNZ-ClO₄ Ethanol 231 5.35 × 10⁻² KClO₄Ethanol 0.27 7.36 × 10⁻⁸

As clearly evident from Table 1, BNZ-ClO₄ solubility product is largerin six orders of magnitude in ethanol compared to the solubility productin deionized water, and five orders of magnitude larger than thesolubility in salt water.

Thus, BNZ-ClO₄ complex that is a product of water treatment forperchlorate removal by precipitation of BNZ-ClO₄ can be treated bydissolving the complex in ethanol, precipitation ClO₄ in the ethanol andthen evaporating of the ethanol.

An exemplary schematic diagram of a process according to this disclosureis shown in FIG. 1. Into reaction vessel 106, a slurry oforganocation-perchlorate salt (e.g. BNZ-ClO₄) and a solution of a firstsalt (e.g. KOH dissolved in ethanol) are fed via feeding lines 102 and104, respectively. The organocation-perchlorate salt and first salt arebrought into contact in reaction vessel 106, permitting formation oforganic solvent (e.g. ethanol) soluble second salt (e.g. BNZ-OH), andprecipitation of metal-perchlorate (e.g. KClO₄) in solid form due to itsnegligible dissolution in ethanol. A stream 108 of second salt dissolvedin the organic solvent (e.g. BNZ-OH ethanolic solution) mixed with thesolid metal-perchlorate (e.g. KClO₄) is fed into a separation unit 110,from which a stream 112 of the solution of the second salt (e.g. BNZ-OHethanolic solution) is fed into a distillation column 116, separatingthe solution of the second salt into solvent (e.g. ethanol) 120 andwater soluble second salt (which may be in the form of a solid or anaqueous slurry). The second salt (e.g. BNZ-OH) can then be utilized totreat waste water contaminated with perchlorate ions.

From separator 110, a stream 114 of metal-perchlorate in solvent (e.g.KClO₄ in ethanol) slurry is transferred into drier 122, in which thesolvent and the metal-perchlorate streams (124 and 126, respectively)are separated, to result in metal-perchlorate and solvent products.

FIG. 2 shows another variation of the process of this disclosure, inwhich, for the sake of brevity, functionally similar elements to thoseof FIG. 1 were given like numbers, however shifted by 100. For example,reactor 206 in FIG. 2 has the same functionality as reactor 106 in FIG.1.

In FIG. 2, the organic solvent vapor stream 220 from the distillationunit 216 is passed through condenser 232 to obtain organic solventcondensate. Similarly, organic solvent vapors stream 224 from drier 222is passed through condenser 230. The condensate streams are unified intofeed line 234, which feeds organic solvent into mixer 203, to which afeed of first salt 236 is also fed. A solution of the first salt in thesolvent (e.g. KOH in ethanol) is formed in mixer 203, and then fed asfeed stream 204 into reactor 206. In this manner, the organic solventmay be recycled in the process.

An example of a process according to the present disclosure includesfirst mixing a slurry of water-insoluble organocation-perchlorate saltBNZ-ClO₄ with an organic solvent, such as ethanol, to dissolve theBNZ-ClO₄ in the ethanol. The low solubility of KClO₄ in ethanol (i.e.Ks=7.35×10⁻⁸) allows to separate most of the BNZ from the ClO₄ by addingKOH (as the first salt) and precipitating the ClO₄ as KClO₄ (which isethanol insoluble). After the precipitation of the KClO₄ and separationof the BNZ-OH (being the second salt) solution in ethanol, the ethanolis evaporated and BNZ-OH is recovered, and can be re-used for treatinghigh perchlorate concentration in fresh water brackish water or evenbrine (e.g. as described in WO 2014/128702).

Results of recovery of BNZ-OH from BNZ-KCLO4 by treating with KOH inethanol are shown in Tables 2-1 to 2-3.

TABLE 2-1 Step 1: Dissolving BNZ-ClO₄ in ethanol BNZ ClO₄ BNZ-ClO₄ in inin in complex complex ethanol complex ethanol recovery (%) Test (g) (mg)(mg) (mg) (mg) BNZ ClO₄ 1 0.57 269.8 257.6 57.2 29.9 95.5 51.0 2 1.35490.4 381.4 104.0 19.8 77.8 19.0 3 0.55 310.0 293.2 65.7 27.2 94.6 41.3

As seen from Table 2-1, most of the BNZ is dissolved in the ethanol,with most of the tests showing BNZ recovery >90%. This precipitation wasclearly evident as white precipitate that settled at the bottom of thetube after few minutes, in contrast to the BNZ-ClO₄ complex that floatedin the source solution (due to the different densities of thesesolids—0.94 g/cm³ and 2.2 g/cm³ for BNZ-ClO₄ complex and KClO₄,respectively).

The recovery of the ClO₄ was lower, as once the BNZ-ClO₄ complex isdissolved in the ethanol, some ClO₄ precipitates as KClO₄ in thepresence of potassium ions that was attributed to drag out from thesource solution (i.e. BNZ-ClO₄ slurry) that had K/ClO₄ ratio >50.

After dissolving the BNZ-ClO₄ in the ethanol, the ethanol contains BNZ,ClO₄ and any drag out from the source solution. At this point the goalis to remove as much ClO₄ from the ethanol in order to BNZ which issubstantially ClO₄-free. This is carried out by utilizing potassiumions, in order to precipitate KClO₄ out of the ethanol, as shown inTable 2-2.

TABLE 2-2 step 2: Dosing KOH to the ethanol solution BNZ (mg) ClO₄KOH/ClO₄ Before After Before After Ethanol molar KOH KOH KOH KOHRecovery (%) Test (ml) ratio addition addition addition addition BNZClO₄ 1 5 0.86 128.8 137.4 28.6 16.6 106.6 58.1 0 5 2.01 190.7 182.6 9.98.5 95.7 85.8 3 8.8 1.15 252.1 250.1 23.4 3.0 99.2 12.8

As seen from Table 2-2, the addition of KOH reduced the perchlorateconcentration from >20 mg/l to <10 mg/l. During this stage nosignificant loss of BNZ was found as the BNZ recovery was >95%.

The last stage in the BNZ recovery process was evaporation of theethanol and measurement of the BNZ that was left in the sample. Nosignificant losses of BNZ during evaporation were found, as the recoveryof BNZ was ≥95%, as seen from Table 2-3. Recovery that is >100% isattributed to experiment limitation.

TABLE 2-3 step 3: ethanol evaporation Ethanol BNZ in BNZ recovery afterBNZ Test (ml) ethanol (mg) evaporation (mg) recovery (%) 1 3 82.4 94.2114.3 2 3 109.5 114.4 104.4 3 0.4 11.4 10.8 95.0

The BNZ recovery percentage for each step of the process staged therecovery percentage was >92.9% , and the overall (steps 1+2+3) recoverywas 94.4% (±19.9%). This results implies that it is possible to recoverthe BNZ with efficiency that is close to 100%.

1. A process for recovering a water-soluble organocation salt from asubstantially water-insoluble organocation-perchlorate, the processcomprising: (a) contacting said substantially water-insolubleorganocation-perchlorate with a first solution containing a first saltdissolved in an organic solvent, the first salt consisting of a metalcation and a balancing anion, under conditions permitting precipitationof metal-perchlorate salt and formation of a second salt dissolved insaid organic solvent, the second salt consisting of the organocation andthe balancing anion; (b) separating the metal-perchlorate salt from theorganic solvent in which the second salt is dissolved; and (c)separating the organic solvent from the second salt to obtain saidsecond salt, said second salt being a water-soluble organocation salt.2. The process of claim 1, wherein the separating in step (c) is carriedout by evaporation of the organic solvent.
 3. (canceled)
 4. The processof claim 2, wherein step (c) further includes condensing vapors of theorganic solvent formed during evaporation or distillation to obtain acondensate of organic solvent.
 5. (canceled)
 6. The process of claim 1,wherein said separating in step (b) is carried out by sedimentation,decantation, filtration, flotation or a combination thereof.
 7. Theprocess of claim 1, wherein metal-perchlorate salt separated in step (b)is further treated to remove the organic solvent from themetal-perchlorate salt.
 8. The process of claim 7, wherein the organicsolvent is removed from the metal-perchlorate salt by evaporating. 9.The process of claim 8, wherein the organic solvent removed from themetal-perchlorate salt is reintroduced into the process in step (a). 10.The process of claim 1, wherein said substantially water-insolubleorganocation-perchlorate salt is introduced into step (a) in the form ofan aqueous slurry.
 11. The process of claim 1, wherein the molar ratiobetween the water-insoluble organocation salt and the first salt is in arange between 1:1 and 1:10.
 12. The process of claim 1, wherein saidorganocation has is an organocation of formula (I):

wherein R is a —(C₃-C₁₈)alkyl; R₁ and R₂ are each independently selectedfrom H and —(C₁-C₆)alkyl; and R₃ is one or more substituents, eachindependently selected from H, —(C₁-C₆)alkyl, —(C₁-C₆)alkoxy,—NHCO(C₁-C₆)alkyl, —OH, and —NH_(2.)
 13. The process of claim 12,wherein R₁ and R₂ are each independently selected from H and methyl. 14.The process of claim 12, wherein R₃ is one or more substituent, eachindependently selected from H, methyl, ethyl and propyl.
 15. The processof claim 12, wherein R₁ and R₂ are both H, and R₃ is a methyl. 16.(canceled)
 17. The process of claim 12, wherein R is a —(C₆-C₁₈)alkyl.18. (canceled)
 19. The process of claim 12, wherein organocation isbenzalkonium in which R is a —(C₃-C₁₈)alkyl.
 20. (canceled)
 21. Theprocess of claim 1, wherein said metal is selected from sodium,potassium, calcium and magnesium.
 22. (canceled)
 23. The process ofclaim 1, wherein the balancing anion is selected from hydroxyl,carboxyl, halogen, and oxyanion.
 24. (canceled)
 25. The process of claim1, wherein said organic solvent is selected from ethanol, isopropanol,acetone, methanol, and mixtures thereof.
 26. (canceled)
 27. A processfor obtaining water-soluble benzalkonium-hydroxide from substantiallywater-insoluble benzalkonium-perchlorate, the process comprising: (a)contacting an aqueous slurry of benzalkonium-perchlorate with a firstsolution containing potassium hydroxide dissolved in an organic solvent,under conditions permitting precipitation of potassium-perchlorate saltand formation of benzalkonium-hydroxide dissolved in said organicsolvent; (b) separating the precipitated potassium-perchlorate from theorganic solvent in which the benzalkonium-hydroxide is dissolve; and (c)separating the organic solvent from the benzalkonium-hydroxide to obtaina water-soluble benzalkonium-hydroxide, benzalkonium having thefollowing formula (I):

wherein R is a —(C₃-C₁₈)alkyl; R₁ and R₂ are each independently selectedfrom H and —(C₁-C₆)alkyl; and R₃ is one or more substituents, eachindependently selected from H, —(C₁-C₆)alkyl, —(C₁-C₆)alkoxy,—NHCO(C₁-C₆)alkyl, —OH, and —NH_(2.)
 28. The process of claim 27,wherein R1 and R2 are each methyl, R3 is H, and R is a —(C3-C18)alkyl.29. (canceled)